[meta-xilinx] [PATCH] image_types_zynq.bbclass: introduce an SD/eMMC image creation class

[Nathan Rossi]

On 15 March 2017 at 11:00, Jean-Francois Dagenais
<jeff.dagenais at gmail.com> wrote:
>
>> On Mar 14, 2017, at 08:24, Nathan Rossi <nathan at nathanrossi.com> wrote:
>>
>> I am not sure if you were aware but there is a tool that is part of OE
>> called 'wic' that can be used for creating complete disk images like
>> you have done in this bbclass.
>> http://www.yoctoproject.org/docs/latest/dev-manual/dev-manual.html#creating-partitioned-images
>
> I was aware of it yeah. Just thought it was cumbersome to have to invoke more
> build steps after "bitbake" in order to get my end artifact. We did some
> prototyping on an i.mx6 prior to the zynq platform. This class was inspired from
> a similar bbclass found in meta-fsl-arm
> (https://github.com/Freescale/meta-fsl-arm/blob/master/classes/image_types_fsl.bbclass)
>
>>
>> There is an example which approximately resembles your sdcard layout
>> here: http://git.openembedded.org/openembedded-core/tree/scripts/lib/wic/canned-wks/sdimage-bootpart.wks.
>> The "bootimg-partition" populates from files defined by the
>> "IMAGE_BOOT_FILES" variable. e.g.
>> http://git.yoctoproject.org/cgit/cgit.cgi/meta-xilinx/tree/conf/machine/zc702-zynq7.conf#n27
>
> I think it has some value. In all previous projects, bitbake would always build
> everything we need to output. We particularly made use of the hddimg FS_TYPE. I
> just don't see why an external "wic" had to be invented in the first place...
> you can perfectly do everything by extending the existing IMAGE_TYPES framework.

You can get the same behavior using the "wic" image fstype. e.g.

IMAGE_FSTYPES = "wic"
WKS_FILES = "sdimage-bootpart.wks"

There are advantages/disadvantages to both wic and image fstypes.
Though I just wanted to make sure you were aware of wic for this sort
of task.

Regards,
Nathan